The present invention relates generally to the packaging of computer peripheral cards and more particularly to the manufacture of peripheral cards such as PCMCIA cards having injection molded housings.
The widespread use of personal computers has brought about a subsequent demand for expansion boards to enhance their functions. Originally, these boards were mounted internally and therefore required the opening of the computer. However, the advent of the laptop personal computer and handheld computers brought about the development of the portable expansion board called a peripheral or PCMCIA card. PCMCIA cards are inserted in external slots of a laptop or handheld computer without the inconvenience of opening the computer. Their small size and portability allow easy interchange of applications by merely plugging and unplugging different peripheral cards into the external slots of the computer or other electronic device. "PCMCIA" refers to an industry standard for packaging these peripheral cards. Common peripherals available in PCMCIA format include modems, wireless communicators, and memory boards.
A PCMCIA card 10 constructed in a conventional fashion is depicted in FIG. 1. A printed circuit board 15 is electrically coupled to a female PCMCIA connector 20. If the card contains a wireless communicator, it typically requires radio frequency (RF) shields 25 to prevent interference with the computer. The circuit board 15 fits in a groove or shelf in a plastic rim 30 surrounding the circuit board. Sheet metal jackets 35 are attached to the top and bottom of the assembly to form the complete PCMCIA card 10. The metal jackets 35 do provide some RF shielding, but their primary purpose is to provide structural integrity.
Unfortunately, the process of assembling this conventional peripheral card and the assembled card itself possess certain drawbacks. First, the manufacturing process must align and attach several parts: the board, the edge connector, the plastic rim, the RF shields, and the metal jackets. This multistage assembly process is time consuming and labor intensive and therefore quite costly. Second, the use of a plastic rim wastes valuable printed circuit board real estate. Third, the sheet metal jackets are generally fairly flexible implying a relatively weak external protective structure for the board. These drawbacks could be overcome by a method of manufacturing peripheral cards such that the resulting card would have a solid, one-piece, housing replacing the plastic rim and metal jackets.